Effect of monensin on in vitro fermentation of maize starch by hindgut contents of cattle
SUMMARYContents of the caecum and the colon of four steers and four cows fed concentrate-plus-roughage diets were obtained at an abattoir, transferred to the laboratory and incubated anaerobically with maize starch in the presence (10mg/l) or absence of monensin. Samples taken at the end of incubation were assayed for fermentation acids and methane production.Monensin significantly increased the molar percentage of propionate and decreased that of butyrate. Acetate percentage was not significantly influence by the addition of monensin. There was no consistent effect of monensin on total volatile fatty acid concentrations. Monensin decreased methanogenesis in all incubations. The production of methane was small, only 1 mmol/13–50 mmol of volatile fatty acid.